Improvement in printing-telegraphs



G. L. ANDERS.

PRINTING TELEGRAPH. N.173,7 50. Patented IFeb. zz, 187e.

'UNITED N STATES PATENT QEECE. N

GEORGE L. ANDERS, OE BOSTON, ASSIGNOR TO E. R. WELCH, OE CAMBRIDGE, MASSAGHUSETTS.

IMPRovl-:wnalar.IN PRlNTiNe-TELEGRAPHS.

Speciricationforming,part of Letters Patent No. 173,750, dated February A22, 1876 ,application filed January 2 4, 1876.`

To all whom it may concern e Be it known that I, GEORGE L. ANDERS, of Boston, in the county of Suii'olk, State of Massachusetts, have invented a 4new and useful AImprovement in Telegraph Apparatus, of

which the following is a full, clear, and exact description, reference being -had to the draw ings accompanying and making part of this specification.

The invention relates to amethod of setting or adjusting the pointer ot' a dial-telegraph, or the type-wheel of a printing-telegraph, to a certain determinate point, for the purp'ose of enabling two ormore such instruments to work in unison.

The principle uponwhich the invention is made and operated is as follows: It is obvious that any machine which derives its motionfrom a eonstant source of power will cease ,to move whenever the force exerted b`y the power is reduced to a strength equal to the resistance offered by the machine, and that, therefore,

the machine can be arrested at any determinate point by the interposition at that point ot' a `resistance greater than can be overcome by the power. y Y

In dial or printing` telegraph instruments in which the pointer or type-wheel moves with a stepby-step motion these parts are either `moved directly by the action of a propelling device operating intermittently upon a toothed wheel on their shafts by electromagnetism, or by a train driven by any suitable power which imparts to the shaft a constant tendency to rotate, and the motionof which is controlled by a suitable escapement acting intermittently by electro-magnetism. Itis obvious, therefore, that in order to move the mechanism the electric current must not fall below a certain strength; and it'isV also ob-` viousthat it' an obstruction or resistance to the movement ot' the mechanism greater than can be overcome by then power of the current be'interposed at a certain determinate point the movement of thev mechanism will be arrested at that point trolled in its movement bythe action of an escapement operated by electro magnetism and a toothed wheel, a stop or mechanical ob'- struction offering a resistance which is readily overcome by the power derived from currents of the strength ordinarily usedin working the apparatus, but which can not be overcome when these currents are weakened, and will, therefore, cause the movement ot' the mechanism to be arrested, arranged ata certain determinate point in relation to the movement of the pointer or type-wheel, and in providing a means for weakening the current, whereby two or more telegraph-instruments ot' the kind referred to, working together on the same line, can be stopped lat any determinate point as often as may be necessary to keep their pointers or type-wheels movingin unison.

The accompanying drawing shows the means which'I adopt for carrying my invention i'nto eii'ect in both classes ot' dial or printing telegraph-instruments referred to, Figures 1,2, and 4 Vshowing the improvement applied to that class of such telegraphs in which a train ot' wheels is used, and Figs.- 3 and showing the improvement applied to that class o'f 'such telegraphs in which motion is given by propelling mechanism,

In these drawings similar letters refer to similar parts.

Referring tov Figi, A is a train whichmoves the shaft ot'l the pointer or type-wheel. B is theescape or toothed wheel, which is constructed in the usual manner, with the exception that one toothyb, at the zero or unison point is slightly wider than the other teeth, a4

a a. C is the escapement, also constructed in` the usual manner. lai-ized magnet for Operating the escapement, `and D its armature; c, a spring attached to 'the controlling-armature, of such strength that it will be bent over the extremity of the arm f, forced to the side ot' the magnet when the currents are of the ordinary force, so as to permit the escapement'to have sufficient movement to permit all of the teeth to pass one by one, the wide tooth b as well as the smaller teeth: a a a, but will not be bent' sufficiently when th'e current is weakened to permit any M M is an ordinary po- I ot' the teeth.

but the small teeth to pass, and consequently the wide tooth, not being able to go by the For example, the tooth at the zero or unison point may be longer, rather than wider, than the other teeth; or, instead of a wide tooth, a stop may be placed on the Wheel near one y The spring may be attached to the armature in a different manner, or may Y be a spiral spring encircling a pin'sliding in or 011 the magnet, and arranged so as to abut against the armature, or may be attached to one of the teeth of the wheel, and so adjusted that it will yield to the escapement when op lerated by strong currents, but not when the escapemeut `is operated by weak currents; or,

v `in place of a spring alone, an auxiliary magnet may be used for limit-ing the movement ofthe pallets, as shown in Fig. 4, the spring of the auxiliary magnet in this case being the mechanical obstruction,l which cannot be overcome by weak currents; or the stop on the toothed wheel may bev under the control of an auxiliary magnet.-

rlhe manner of constructing these various methods of carrying my invention into effect f will be apparent to those skilled in the art to which it belongs.

In Figs. 3 and 5 my invention is shown as applied to a dial or printing telegraph, in which the shaft of the pointer or type-wheel is directly driven by propelling mechanism. operated by electro-magnetism.

B is the toothed wheel ony the shaft of the pointer or type-wheel. O is the propellingescapement. M M is the magnet; b, a'n-arm attached to the shaft of the pointer or dial at the zero-point; f, a spring bearing against l the extremity of the 'arm b with force sufcient as not to allow the arm to pass when the strength of the current is weakened.

In this form of the invention .the resistance yis opposed by only one current on the line during one revolution of the type-wheel or pointer, which will overcome the resistance if the current is strong, but will not overcome it when weakened; and this principle of con struction may be applied in various ways-as, for instance, instead of the armb and spring l j', one'of the teeth ofthe Wheel may be slight- -ly larger than the others, and a spring may ybe attached to the propelling mechanism, the ktension of whichy will not be overcome when ,the current is weakened, and, consequently, vthe escapement will then stick on the large tooth. This'form is shown in Fig. 5; 'or, in..-

.stead ofthe spring j', a stop controlled by The invention is applicable to any form of printing or dial telegraph in whichthe magnets moving or controlling the movement of the pointer or type-wheel are in the mainline circuit, whether the printing-magnet is in the same circuit as the type-wheel magnets or in an independent circuit, or whether the printing mechanism is operated by'increasing, prolonging, or interrupting the'linecurrent, or by mechanical means.

rlhe weakening of the current may be'eft'ected either by reducing the strength of the battery, or by the interposition of a resistance in the circuit.' The manner in which this is done is well known, and any method now used may be adopted. It may be automatically effected at the transmitter, or may be under the control of the operator, so as to be e'ected at any desired time, not only for the purpose of making a unison, but also for calling the attention of the receiving-operator to any inaccuracy in the printing, by stopping the action of his type-wheel at lthe unisnor zero point.

What I claim as my invention, and desire to secure by Letters Patent, is

l. In a dial or printing telegraph instrument, in which the pointer or typewheel controlling magnets are in the main-line circuit, the combination, with the mechanism controlling the movement ofthe pointer or type-wheel, of a mechanical obstruction, snhstantially as described, fixed at a certain determinate point in relation to the Amovement of the pointer or type-wheel, and offering a resistance which is readily overcome by the currents ordinarily used for working the apparatus, but cannot be overcome when the currents are weakened below their ordinary strength, and a means for weakening the linecurrent, as described, substantially as and for the purpose set forth.

2. The combination of the toothed wheel B, having a wide tooth, b., or its equivalent, the escapement G, the magnet M M, and spring e and arm f, or their equivalents, substantially as and for the purpose set forth.

GEORGE L. ANDERS. Witnesses:

ALEX. L. HAYES, J AMEs WALLACE. f 

